The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 27, 1999
Filed:
Dec. 22, 1997
Subhas Bothra, San Jose, CA (US);
Harlan Lee Sur, Jr, San Leandro, CA (US);
VLSI Technology, Inc., San Jose, CA (US);
Abstract
Disclosed is a method for making a semiconductor pressure transducer structure in CMOS integrated circuits. The method includes patterning a first metallization layer that lies over an first oxide layer to produce a first patterned metallization layer that is not in electrical contact with a substrate. Forming a tungsten plug in a second oxide layer that overlies the first patterned metallization layer, such that the tungsten plug is in electrical contact with the first patterned metallization layer. Patterning a second metallization layer that overlies the first patterned metallization layer and the tungsten plug to produce a second patterned metallization layer. The patterning of the second metallization layer is configured to prevent the second patterned metallization layer from completely overlying the tungsten plug. The method further includes submerging the pressure transducer structure in a basic solution having a pH level that is greater than about 7. In this manner, the tungsten plug will come in direct contact with the basic solution that causes the tungsten plug to be removed while the pressure transducer structure is submerged in the basic solution.